Following a similar method as in [1]} the constant term along any unipotent radical \(U^{\prime }\)  of the parabolic subgroup \(P^{\prime } = M^{\prime }U^{\prime }\)  of the Eisenstein series \(E(\tilde{\varphi },g)\)  can be written as the integral:
\(c_{P^{\prime }}E(\tilde{\varphi },g)=\sum _{\gamma \in P(k)\backslash G(k)}\int _{U^{\prime }(k)\backslash U^{\prime }(\mathbb {A})}\varphi (\gamma u^{\prime } g)du^{\prime }.\) 
